Heating and cooling of viscous food products

ABSTRACT

An improved heat exchange system and methodology, and an improved material treatment system and methodology, based on that heat exchange system, for providing improved pasteurized and sterilized packaged food products is disclosed. Improved pasteurized and sterilized packaged food products produced thereby are also disclosed.

FIELD OF THE INVENTION

[0001] The present invention relates to heat exchange generally and moreparticularly to sterilization of food products using highly efficientheat exchangers.

BACKGROUND OF THE INVENTION

[0002] The following U.S. Pat. Nos. of the applicant are related to thesubject matter of the present invention: 6,158,504; 5,928,699, 5,670,198and 5,768,472.

SUMMARY OF THE INVENTION

[0003] The present invention seeks to provide an improved heat exchangerand improved pasteurized and sterilized food products realized by use ofthe improved heat exchanger.

[0004] There is thus provided, in accordance with a preferred embodimentof the present inventions a vacuum heat exchange system including:

[0005] a container partially filled with a liquid and maintained under avacuum;

[0006] a first heat exchanger disposed in the liquid in the container,the first heat exchanger receiving, a first fluid material, heating theliquid and thereby cooling the first fluid material; and

[0007] a second heat exchanger disposed outside of the liquid in thecontainer, the second heat exchanger receiving a second fluid materialand being heated by vapors of the liquid, thereby heating the secondfluid material,

[0008] at least one of the first and second heat exchangers including anagitator for agitating, the fluid material passing therethrough toenhance heat exchange generally throughout the fluid material.

[0009] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material. Additionally or alternatively,both of the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0010] In accordance with a preferred embodiment of the presentinvention, at least one of the first and second heat exchangers includesa scraped surface heat exchanger.

[0011] Additionally, the vacuum heat exchange system also includes anelectroheater for heating the first fluid material prior to receiptthereof by the first heat exchanger. Alternatively, the vacuum heatexchange system also includes an electroheater for receiving the secondfluid material from the second heat exchanger.

[0012] In accordance with a preferred embodiment of the presentinvention, the first and second fluid materials are the same material atdifferent temperatures and the vacuum heat exchange system also includesan electroheater for heating the first fluid material prior to receiptthereof by the first heat exchanger and the first fluid material isreceived by the electroheater from the second heat exchanger.

[0013] There is also provided, in accordance with a preferred embodimentof the present invention, a material treatment system including:

[0014] an electroheater operative to rapidly heat a first fluidmaterial; and

[0015] a vacuum heat exchange subsystem operative to rapidly cool thefirst fluid material following electroheating thereof, the vacuum heatexchange subsystem including:

[0016] a container partially filled with a liquid and maintained under avacuum;

[0017] a first heat exchanger disposed in the liquid in the container,the first heat exchanger receiving the first fluid material, heating theliquid and thereby cooling the first fluid material; and

[0018] a second heat exchanger disposed outside of the liquid in thecontainer, the second heat exchanger receiving a second fluid materialand being heated by vapors of the liquid, thereby heating the secondfluid material,

[0019] at least one of the first and second heat exchangers including anagitator for agitating the fluid material passing therethrough toenhance heat exchange generally throughout the fluid material.

[0020] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material Additionally or alternatively, bothof the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0021] In accordance with a preferred embodiment of the presentinvention, at least one of the first and second heat exchangers includesa scraped surface heat exchanger.

[0022] In another preferred embodiment of the present invention theelectroheater supplies the first fluid material to a holding tank, priorto receipt of the first fluid material by the first heat exchanger.Alternatively or additionally, the electroheater receives the secondfluid material from the second heat exchanger.

[0023] In accordance with still another preferred embodiment of thepresent invention, the first and second fluid materials are the samematerial at different temperatures and the electroheater heats the firstfluid material prior to receipt thereof by the first heat exchanger andthe first fluid material is received by the electroheater from thesecond heat exchanger.

[0024] There is additionally provided, in accordance with a preferredembodiment of the present invention, a material treatment systemincluding:

[0025] electroheater operative to rapidly heat a first fluid material;

[0026] a first vacuum heat exchange subsystem operative to rapidly coolthe first fluid material following electroheating thereof, the firstvacuum heat exchange subsystem including:

[0027] a container partially filled with a liquid and maintained under avacuum;

[0028] a first heat exchanger disposed in the liquid in the container,the first heat exchanger receiving the first fluid material, heating theliquid and thereby cooling the first fluid material; and

[0029] a second heat exchanger disposed outside of the liquid in thecontainer, the second heat exchanger receiving a second fluid materialand being heated by vapors of the liquid, thereby heating the secondfluid material,

[0030] at least one of the first and second heat exchangers including anagitator for agitating the fluid material passing therethrough toenhance heat exchange generally throughout the fluid material; and

[0031] a second vacuum heat exchange subsystem operative to preheat thefirst fluid material prior to electroheating thereof, the second vacuumheat exchange subsystem including:

[0032] a container partially filled with a liquid and maintained under avacuum;

[0033] a third heat exchanger disposed in the liquid in the container,the third heat exchanger receiving a third fluid material, heating theliquid and thereby cooling the third fluid material; and

[0034] a fourth heat exchanger disposed outside of the liquid in thecontainer, the fourth heat exchanger receiving the first fluid materialand being heated by vapors of the liquid, thereby heating the firstfluid material,

[0035] at least one of the third and fourth heat exchangers including anagitator for agitating, the fluid material passing therethrough toenhance heat exchange generally throughout the fluid material.

[0036] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material. Additionally or alternatively,both of the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0037] In accordance with a preferred embodiment of the presentinvention, the third heat exchanger includes an agitator for agitatingthe third fluid material passing therethrough to enhance heat exchangegenerally throughout the third fluid material. Alternatively, the fourthheat exchanger includes an agitator for agitating the first fluidmaterial passing therethrough to enhance heat exchange generallythroughout the first fluid material. Additionally or alternatively, bothof the third and fourth heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0038] In accordance with a preferred embodiment of the presentinvention, at least one of the first and second heat exchangers includesa scraped surface heat exchanger. Additionally or alternatively, atleast one of the third and fourth heat exchangers includes a scrapedsurface heat exchanger.

[0039] In another preferred embodiment of the present invention, theelectroheater supplies the first fluid material to a holding tank, priorto receipt of the first fluid material by the first heat exchanger.

[0040] There is further provided, in accordance with a preferredembodiment of the present invention, a packaged food productcharacterized in:

[0041] having a viscosity exceeding approximately 5,000 centipoise;

[0042] being sterilized; and

[0043] being aseptically packaged.

[0044] Preferably, the packaged food product has a pH exceedingapproximately 4.5.

[0045] There is yet further provided, in accordance with a preferredembodiment of the present invention, a packaged humus food productcharacterized in:

[0046] being sterilized; and

[0047] being aseptically packaged.

[0048] There is still further provided, in accordance with a preferredembodiment of the present invention, a packaged egg food productcharacterized in:

[0049] being sterilized; and

[0050] being aseptically packaged.

[0051] There is additionally provided, in accordance with a preferredembodiment of the present invention, a packaged egg food productcharacterized in:

[0052] being sterilized; and

[0053] being aseptically filled and sealed following sterilization andcooling thereof.

[0054] Preferably, the packaged egg food product is coagulated.

[0055] There is further provided, in accordance with a preferredembodiment of the present invention, a packaged egg food productcharacterized in:

[0056] being pasteurized to at least 75 degrees Centigrade;

[0057] being aseptically filled and sealed following pasteurization andcooling thereof; and

[0058] being liquid.

[0059] There is also provided, in accordance with a preferred embodimentof the present invention, a vacuum heat exchange method including:

[0060] partially filling a container maintained under a vacuum with aliquid;

[0061] receiving a first fluid material in a first heat exchangerdisposed in the liquid in the container, heating the liquid and therebycooling the first fluid material; and

[0062] receiving a second fluid material in a second heat exchangerdisposed outside of the liquid in the container, heating the second heatexchanger by vapors of the liquid, thereby heating the second fluidmaterial,

[0063] where at least one of the first and second heat exchangersincludes an agitator for agitating the fluid material passingtherethrough to enhance heat exchange generally throughout the fluidmaterial.

[0064] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material. Additionally or alternatively,both of the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0065] In accordance with a preferred embodiment of the presentinvention, at least one of the first and second heat exchangers includesa scraped surface heat exchanger.

[0066] In another preferred embodiment of the present invention, thevacuum heat exchange method also includes heating the first fluidmaterial in an electroheater prior to receipt thereof by the first heatexchanger. Additionally or alternatively, the vacuum heat exchangemethod also includes receiving the second fluid material into anelectroheater from the second heat exchanger.

[0067] In yet another preferred embodiment of the present invention, thefirst and second fluid materials are the same material at differenttemperatures and the vacuum heat exchange method also includes:

[0068] receiving the first fluid material from the second heatexchanger; and

[0069] heating the first fluid material using an electroheater prior toreceipt thereof by the first heat exchanger.

[0070] There is further provided, in accordance with a preferredembodiment of the present invention, a material treatment methodincluding:

[0071] rapidly heating a first fluid material using an electroheater;and

[0072] rapidly cooling the first fluid material following electroheatingthereof by:

[0073] partially filling a container maintained under a vacuum with aliquid;

[0074] receiving, the first fluid material in a first heat exchangerdisposed in the liquid in the container, heating the liquid and therebycooling the first fluid material; and

[0075] receiving a second fluid material in a second heat exchangerdisposed outside of the liquid in the container, heating the second heatexchanger by vapors of the liquid, thereby heating the second fluidmaterial,

[0076] where at least one of the first and second heat exchangersincludes an agitator for agitating the fluid material passingtherethrough to enhance heat exchange generally throughout the fluidmaterial.

[0077] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material. Additionally or alternatively,both of the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0078] In accordance with a preferred embodiment of the presentinvention, at least one of the first and second heat exchangers includesa scraped surface heat exchanger.

[0079] In another preferred embodiment of the present invention, thevacuum heat exchange method also includes supplying the first fluidmaterial to a holding tank from the electroheater prior to receiving thefirst fluid material in the first heat exchanger. Additionally oralternatively, the vacuum heat exchange method also includes receivingthe second fluid material into the electroheater from the second heatexchanger.

[0080] In still another preferred embodiment of the present invention,the first and second fluid materials are the same material at differenttemperatures and the vacuum heat exchange method also includes:

[0081] receiving the first fluid material by the electroheater from thesecond heat exchanger; and

[0082] heating the first fluid material in the electroheater prior toreceipt thereof by the first heat exchanger.

[0083] There is yet further provided, in accordance with a preferredembodiment of the present invention, a material treatment methodincluding:

[0084] rapidly heating a first fluid material using an electroheater;and

[0085] rapidly cooling the first fluid material following electroheatingthereof by:

[0086] partially filling a container maintained under a vacuum with aliquid;

[0087] receiving a first fluid material in a first heat exchangerdisposed in the liquid in the container, heating the liquid and therebycooling the first fluid material; and

[0088] receiving a second fluid material in a second heat exchangerdisposed outside of the liquid in the container, heating the second heatexchanger by vapors of the liquid, thereby heating the second fluidmaterial,

[0089] where at least one of the first and second heat exchangersincludes an agitator for agitating the fluid material passingtherethrough to enhance heat exchange generally throughout the fluidmaterial; and

[0090] preheating the first fluid material prior to electroheatingthereof by:

[0091] partially filling a container maintained under a vacuum with aliquid;

[0092] receiving a third fluid material in a third heat exchangerdisposed in the liquid in the container, heating the liquid and therebycooling the third fluid material; and

[0093] receiving the first fluid material in a fourth heat exchangerdisposed outside of the liquid in the container, heating the fourth heatexchanger by vapors of the liquid, thereby heating the first fluidmaterial,

[0094] where at least one of the third and fourth heat exchangersincludes an agitator for agitating the fluid material passingtherethrough to enhance heat exchange generally throughout the fluidmaterial.

[0095] Preferably, the first heat exchanger includes an agitator foragitating the first fluid material passing therethrough to enhance heatexchange generally throughout the first fluid material. Alternatively,the second heat exchanger includes an agitator for agitating the secondfluid material passing therethrough to enhance heat exchange generallythroughout the second fluid material. Additionally or alternatively,both of the first and second heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0096] In accordance with a preferred embodiment of the presentinvention, the third heat exchanger includes an agitator for agitatingthe third fluid material passing therethrough to enhance heat exchangegenerally throughout the third fluid material. Alternatively, the fourthheat exchanger includes an agitator for agitating the first fluidmaterial passing therethrough to enhance heat exchange generallythroughout the first fluid material Additionally or alternatively, bothof the third and fourth heat exchangers include an agitator foragitating the fluid material passing therethrough to enhance heatexchange generally throughout the fluid material.

[0097] Preferably, at least one of the first and second heat exchangersincludes a scraped surface heat exchanger. Additionally oralternatively, at least one of the third and fourth heat exchangersincludes a scraped surface heat exchanger.

[0098] In another preferred embodiment of the present invention, thematerial treatment method includes supplying the first fluid material toa holding tank from the electroheater prior to receiving, the firstfluid material in the first heat exchanger.

[0099] There is additionally provided, in accordance with a preferredembodiment of the present invention, a method of preparing a packagedfood product including:

[0100] producing a food product having a viscosity exceedingapproximately 5,000 centipoise;

[0101] sterilizing the food product; and

[0102] aseptically packaging the food product.

[0103] Preferably, the packaged food product has a pH exceedingapproximately 4.5.

[0104] There is further provided, in accordance with a preferredembodiment of the present invention, a method of preparing a packagedhumus food product including:

[0105] sterilizing the humus food product; and

[0106] aseptically packaging the humus food product.

[0107] There is still further provided, in accordance with a preferredembodiment of the present invention, a method of preparing a packagedegg food product including:

[0108] sterilizing the egg food product; and

[0109] aseptically packaging the egg food product.

[0110] There is yet further provided, in accordance with a preferredembodiment of the present invention, a method of preparing a packagedegg food product including:

[0111] sterilizing the egg food product;

[0112] cooling the egg food product; and

[0113] aseptically filling and sealing the egg food product in apackage.

[0114] Preferably, the egg food product is coagulated.

[0115] There is additionally provided, in accordance with a preferredembodiment of the present invention, a method of preparing a packagedliquid egg food product including:

[0116] pasteurizing the liquid egg food product to at least 75 degreesCentigrade;

[0117] cooling the liquid egg food product; and

[0118] aseptically filling and sealing the liquid egg food product in apackage.

BRIEF DESCRIPTION OF THE DRAWINGS

[0119] The present invention will be understood and appreciated morefully from the following detailed description, taken in conjunction withthe drawings in which:

[0120]FIG. 1A is a simplified sectional illustration of a vacuum heatexchange system constructed and operative in accordance with a preferredembodiment of the present invention;

[0121]FIG. 1B is a sectional illustration of a portion of an agitatoroperative in accordance with a preferred embodiment of the presentinvention;

[0122]FIG. 2 is a simplified sectional illustration of a vacuum heatexchange system constructed and operative in accordance with anotherpreferred embodiment of the present invention;

[0123]FIG. 3 is a simplified sectional illustration of a vacuum heatexchange system constructed and operative in accordance with stillanother preferred embodiment of the present invention;

[0124]FIG. 4 is a simplified sectional illustration of a materialtreatment system and methodology constructed and operative in accordancewith a preferred embodiment of the present invention;

[0125]FIG. 5 is a simplified sectional illustration of a materialtreatment system and methodology constructed and operative in accordancewith another preferred embodiment of the present invention;

[0126]FIG. 6 is a temperature-time graph illustrating aspects ofoperation of embodiments of the present invention;

[0127]FIG. 7 is a simplified illustration of an electroheating systemuseful with highly viscous materials and products containing particles;and

[0128]FIG. 8 is a simplified sectional illustration of a materialtreatment system and methodology constructed and operative in accordancewith yet another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0129] Reference is now made to FIGS. 1A and 1B, which are simplifiedsectional illustrations of a vacuum heat exchange system constructed andoperative in accordance with a preferred embodiment of the presentinvention As seen in FIG. 1A, the vacuum heat exchange system preferablyincludes a thermally insulated enclosure 100, the interior of whichcommunicates with the ambient atmosphere via a vacuum pump 102, whichpreferably maintains the interior of enclosure 100 at subatmosphericpressure, typically about 29″ of mercury.

[0130] Enclosure 100 is partially filled with a cooling liquid 104,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 100. A heated fluid material106, such as a heated food product which has undergone electroheating,is preferably supplied to a conduit 108 which extends through the liquid104. As the heated fluid material 106 passes through the conduit 108, inthermal contact with the walls thereof, it becomes cooled by evaporatingthe liquid 104. The cooled fluid material then flows from the conduit108.

[0131] In accordance with a preferred embodiment of the presentinvention, an agitator 110, typically in the form of an elongate shaft112, having outwardly extending vanes 114, is disposed in conduit 108,and rotated therein about an axis 116, as by a motor 118, to provideenhanced uniformity of thermal contact between the heated fluid material106 and the walls of the conduit 108. A preferred type of conduit 108and agitator 110 are together known as a scraped surface heat exchanger.

[0132] In accordance with a preferred embodiment of the presentinvention a cooling liquid 120, preferably water, is caused to passthrough a conduit 122, preferably a coil, which extends throughenclosure 100, above the level of the cooling liquid 104. Thetemperature of the cooling liquid 120 is preferably sufficiently low asto cause vapors of the cooling, liquid 104 to condense upon contact withthe outer walls of conduit 122 and to fall downward into cooling liquid104, as drops 124.

[0133] Reference is now made to FIG. 2, which is a simplified sectionalillustration of a vacuum heat exchange system constructed and operativein accordance with another preferred embodiment of the presentinvention. As seen in FIG. 2, the vacuum heat exchange system preferablyincludes a thermally insulated enclosure 200, the interior of whichcommunicates with the ambient atmosphere via a vacuum pump 202, whichpreferably maintains the interior of enclosure 200 at subatmosphericpressure, typically about 29″ of mercury.

[0134] Enclosure 200 is partially filled with a cooling liquid 204,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 200. A heated liquid 206,such as heated water, is preferably supplied to a conduit 208,preferably a coil, which extends through the liquid 204. As the heatedliquid 206 passes through the conduit 208, in thermal contact with thewalls thereof, it heats the liquid 204, generating heated vapor 214.

[0135] In accordance with a preferred embodiment of the presentinvention, a cool fluid material 210 is caused to pass through a conduit212, which extends through enclosure 200, above the level of the coolingliquid 204. As the cool fluid material 210 passes through the conduit212, in thermal contact with the walls thereof, it becomes heated by theheated vapor 214 from liquid 204. The heated fluid material then flowsfrom the conduit 212.

[0136] In accordance with a preferred embodiment of the presentinvention, an agitator 220, typically in the form of an elongate shaft222, having outwardly extending vanes 224, is disposed in conduit 212,and rotated therein about an axis 226, as by a motor 228, to provideenhanced uniformity of thermal contact between the cool fluid material210 and the walls of the conduit 212. A preferred type of conduit 212and agitator 220 are together known as a scraped surface heat exchanger.

[0137] Reference is now made to FIG. 3, which is a simplified sectionalillustration of a vacuum heat exchange system constructed and operativein accordance with still another preferred embodiment of the presentinvention. As seen in FIG. 3, the vacuum heat exchange system preferablyincludes a thermally insulated enclosure 300, the interior of whichcommunicates with the ambient atmosphere via a vacuum pump 302, whichpreferably maintains the interior of enclosure 300 at subatmosphericpressure, typically about 29″ of mercury.

[0138] Enclosure 300 is partially filled with a cooling liquid 304,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 300. A heated fluid material306, such as a heated food product which has undergone electroheating,is preferably supplied to a conduit 308, which extends through theliquid 304. As the heated fluid material 306 passes through the conduit308, in thermal contact with the walls thereof, it becomes cooled byevaporating the liquid 304, thereby heating the liquid 304, generatingheated vapor 309. The cooled fluid material then flows from the conduit308.

[0139] In accordance with a preferred embodiment of the presentinvention, an agitator 310, typically in the form of an elongate shaft312, having outwardly extending vanes 314, is disposed in conduit 308,and rotated therein about an axis 316, as by a motor 318, to provideenhanced uniformity of thermal contact between the heated fluid material306 and the walls of the conduit 308. A preferred type of conduit 308and agitator 310 are together known as a scraped surface heat exchanger.

[0140] In accordance with a preferred embodiment of the presentinvention a cool fluid material 320, such as a food product which is tobe electroheated, is caused to pass through a conduit 322, which extendsthrough enclosure 300, above the level of the cooling liquid 304. Thetemperature of the cool fluid material 320 is preferably sufficientlylow as to cause vapors of the cooling liquid 304 to condense uponcontact with the outer walls of conduit 322 and to fall downward intocooling liquid 304, as drops 324. As the cool fluid material 320 passesthrough the conduit 322, in thermal contact with the walls thereof, itbecomes heated by the heated vapor 309 from liquid 304. The heated fluidmaterial then flows from the conduit 322.

[0141] In accordance with a preferred embodiment of the presentinvention, an agitator 330, typically in the form of an elongate shaft332, having outwardly extending vanes 334, is disposed in conduit 322,and rotated therein about an axis 336, as by a motor 338, to provideenhanced uniformity of thermal contact between the cool fluid material320 and the walls of the conduit 322. A preferred type of conduit 322and agitator 330 are together known as a scraped surface heat exchanger.

[0142] Reference is now made to FIG. 4, which is a simplified sectionalillustration of a material treatment system and methodology constructedand operative in accordance with a preferred embodiment of the presentinvention. As seen in FIG. 4, the system and methodology of FIG. 4typically comprises a preheating subsystem 400, such as that shown inFIG. 2 and described hereinabove, which receives a fluid material, suchas a food product, to be preheated and preheats it to a desiredtemperature, an electroheater 402, which heats the preheated fluidmaterial to a predetermined temperature for a predetermined time and acooling subsystem 404, such as that shown in FIG. 1A and describedhereinabove, which receives the electroheated fluid material, typicallyfrom a holding tank 406, cools the fluid material and supplies it to anaseptic filling mechanism 408 after it has been further cooled inconventional cooler 409, thereby producing a packaged product having newand superior characteristics.

[0143] Pre-heating, subsystem 400 preferably comprises a thermallyinsulated enclosure 410, the interior of which communicates with theambient atmosphere via a vacuum pump 412, which preferably maintains theinterior of enclosure 410 at subatmospheric pressure, typically about29″ of mercury.

[0144] Enclosure 410 is partially filled with a liquid 414, preferablywater, which boils at room temperature at the subatmospheric pressure of29″ of mercury within enclosure 410. A heated liquid 416, such as heatedwater, is preferably supplied to a conduit 418, preferably a coil, whichextends through the liquid 414. As the heated liquid 416 passes throughthe conduit 418, in thermal contact with the walls thereof, it heats theliquid 414, generating heated vapor 419.

[0145] In accordance with a preferred embodiment of the presentinvention a cool fluid material to be preheated 420, such as a foodproduct, is caused to pass through a conduit 422, which extends throughenclosure 410, above the level of the cooling liquid 414. As the coolfluid material 420 passes through the conduit 422, in thermal contactwith the walls thereof, it becomes heated by the heated vapor 419 fromliquid 414. The heated fluid material then flows from the conduit 422.

[0146] In accordance with a preferred embodiment of the presentinvention, an agitator 430, typically in the form of an elongate shaft432, having outwardly extending vanes 434, is disposed in conduit 422,and rotated therein about an axis 436, as by a motor 438, to provideenhanced uniformity of thermal contact between the fluid material 420and the walls of the conduit 422. A preferred type of conduit 422 andagitator 430 are together known as a scraped surface heat exchanger.

[0147] The pre-heated output of the scraped surface heat exchanger ispreferably supplied to electroheater 402, which is operative to heat thepre-heated fluid material to an elevated temperature in a very shorttime. Suitable electroheaters are described in applicant's U.S. Pat.Nos. 6,304,718, 6,088,509; 5,863,580; 5,768,472; 5,636,317; 5,609,900;5,607,613; 5,583,960; 5,415,882; 5,290,583 and 4,739,140, thedisclosures of which are hereby incorporated by reference. A preferredembodiment of an electroheater is described hereinbelow with referenceto FIG. 7.

[0148] The heated output of electroheater 402 is preferably supplied viaa holding tank 406 to cooling subsystem 404. Cooling subsystem 404preferably comprises a thermally insulated enclosure 440, the interiorof which communicates with the ambient atmosphere via a vacuum pump 442,which preferably maintains the interior of enclosure 440 atsubatmospheric pressure, typically about 29″ of mercury.

[0149] Enclosure 440 is partially filled with a cooling liquid 444,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 440. The electroheated fluidmaterial 446 is preferably supplied to a conduit 448, which extendsthrough the liquid 444. As the electroheated fluid material 446 passesthrough the conduit 448, in thermal contact with the walls thereof itbecomes cooled by evaporating the liquid 444.

[0150] In accordance with a preferred embodiment of the presentinvention, an agitator 450, typically in the form of an elongate shaft452, having outwardly extending vanes 454, is disposed in conduit 448,and rotated therein about an axis 456, as by a motor 458, to provideenhanced uniformity of thermal contact between the electroheated fluidmaterial 446 and the walls of the conduit 448. A preferred type ofconduit 448 and agitator 450 are together known as a scraped surfaceheat exchanger.

[0151] In accordance with a preferred embodiment of the presentinvention a cooling liquid 460, preferably water, is caused to passthrough a conduit 462, preferably a coil, which extends throughenclosure 440, above the level of the cooling liquid 444. Thetemperature of the cooling liquid 460 is preferably sufficiently low asto cause vapors of the cooling liquid 444 to condense upon contact withthe outer walls of conduit 462 and to fall downward into cooling liquid444, as drops 464.

[0152] The cooled output of cooling subsystem 404 is preferably suppliedto conventional cooler 409 for further cooling prior to being sent toaseptic filling mechanism 408 which produces a packaged product havingenhanced shelf life and storage temperature insensitivity.

[0153] Reference is now made to FIG. 5, which is a simplified sectionalillustration of a material treatment system and methodology constructedand operative in accordance with another preferred embodiment of thepresent invention. As seen in FIG. 5, the system and methodology of FIG.5 typically comprises a preheating and cooling vacuum heat exchangesubsystem 500, such as that shown in FIG. 3 and described hereinabovewhich receives a fluid material, such as a food product, to be preheatedand preheats it to a desired temperature, an electroheater 502, whichrapidly heats the fluid material to a predetermined temperature for apredetermined time and then supplies it to a holding tank 504 and thenceback to subsystem 500 for rapid cooling thereof, and an aseptic fillingmechanism 506, which receives the cold fluid material via a conventionalcooler 508 and produces a packaged product having new and superiorcharacteristics of shelf life and temperature insensitivity.

[0154] As seen in FIG. 5, the vacuum heat exchange system preferablyincludes a thermally insulated enclosure 510, the interior of whichcommunicates with the ambient atmosphere via a vacuum pump 512, whichpreferably maintains the interior of enclosure 510 at subatmosphericpressure, typically about 29″ of mercury.

[0155] Enclosure 510 is partially filled with a cooling liquid 514,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 510.

[0156] In accordance with a preferred embodiment of the presentinvention a fluid material 520, such as a food product which is to beelectroheated, is caused to pass through a conduit 522, which extendsthrough enclosure 510, above the level of the cooling liquid 514. Thetemperature of the fluid material 520 is preferably sufficiently low asto cause vapors of the cooling liquid 514 to condense upon contact withthe outer walls of conduit 522 and to fall downward into cooling liquid514, as drops 524. As the cool fluid material 520 passes through theconduit 522, in thermal contact with the walls thereof, it becomesheated by the heated vapor 526 from liquid 514. The heated fluidmaterial then flows from the conduit 522.

[0157] In accordance with a preferred embodiment of the presentinvention, an agitator 530, typically in the form of an elongate shaft532, having outwardly extending vanes 534, is disposed in conduit 522,and rotated therein about an axis 536, as by a motor 538, to provideenhanced uniformity of thermal contact between the fluid material 520and the walls of the conduit 522. A preferred type of conduit 522 andagitator 530 are together known as a scraped surface heat exchanger.

[0158] The preheated output of conduit 522 is preferably supplied toelectroheater 502, which is operative to heat the pre-heated fluidmaterial to an elevated temperature in a very short time. Suitableelectroheaters are described in applicant's U.S. Pat. Nos. 6,304,718;6,088,509; 5,863,580; 5,768,472; 5,636,317; 5,609,900; 5,607,613;5,583,960; 5,415,882; 5,290,583 and 4,739,140, the disclosures of whichare hereby incorporated by reference. A preferred embodiment of anelectroheater is described hereinbelow with reference to FIG. 7.

[0159] The heated output of electroheater 502 is preferably supplied viaholding tank 504 and a pump 540 to a conduit 542, which extends throughthe liquid 514. As the heated fluid material passes through the conduit542, in thermal contact with the walls thereof, it becomes cooled byevaporating the liquid 514.

[0160] In accordance with a preferred embodiment of the presentinvention, an agitator 550, typically in the form of an elongate shaft552, having outwardly extending vanes 554, is disposed in conduit 542,and rotated therein about an axis 556, as by a motor 558, to provideenhanced uniformity of thermal contact between the heated fluid materialand the walls of the conduit 542. A preferred type of conduit 542 andagitator 550 are together known as a scraped surface heat exchanger.

[0161] Aseptic filling mechanism 506 receives the cooled fluid materialfrom conduit 542 after it has been further cooled in conventional cooler508 and produces a packaged product having new and superiorcharacteristics of shelf life and temperature insensitivity.

[0162] Reference is now made to FIG. 6, which is a temperature-timegraph illustrating operation of the present invention for processingfood products, such as humus, in accordance with preferred embodimentsof the present invention, such as those shown and described hereinabovewith particular reference to FIGS. 4 and 5.

[0163] As seen in FIG. 6, the food product is rapidly preheated by thefirst heat exchanger, such as heat exchanger 400 (FIG. 4) or 500 (FIG.5), typically from a temperature of 40 degrees C. to a temperature of 85degrees C. in approximately 40 seconds. Thereafter, the food product isheated to about 130 degrees C. by the electroheater, such aselectroheater 402 (FIG. 4) or 502 (FIG. 5), in a fraction of a second.It is then cooled to a temperature of 85 degrees C. by the vacuum heatexchanger, such as heat exchanger 404 (FIG. 4) or 500 (FIG. 5), inapproximately 40 seconds, after being held for a period of time in aholding tank at 130 degrees C. It is then preferably cooled further froma temperature of 85 degrees C. to approximately 40 degrees C. or belowbefore being aseptically packaged.

[0164] It has been found by the applicant that humus which has beensterilized by rapid heating and cooling as described hereinabove ischaracterized by having extremely long shelf life without requiringrefrigeration and by having substantial tolerance to temperature abuse.

[0165] It has also been found by the applicant that liquid egg which hasbeen pasteurized by rapid heating, typically to temperatures in therange of 75-85 degrees C., and cooling, similar to that describedhereinabove, is characterized by having extremely long refrigeratedshelf life and by having tolerance to temperature abuse.

[0166] Reference is now made to FIG. 7, which is a simplifiedillustration of an electroheater which is particularly suitable for usewith viscous products, such as humus. As seen in FIG. 7, a viscousproduct, such as humus, typically having a viscosity in the range of20,000 centipoise is supplied at a high rate, typically in the range of1,500 to 5,000 liters/hour through an electrically insulative conduit700, in the direction indicated by arrows 702.

[0167] Three conductive electrodes, 704, 706 and 708 are preferablyarranged in spaced mutual arrangement along conduit 700. Each electrodepreferably includes a hollow disc, the interior of which communicateswith the interior of conduit 700 by means of a plurality of downstreamlydirected angled openings 710. A relatively small quantity of aconductive fluid, typically 1 to 5 liters/hour per electrode, issupplied to conduit 700 from supply conduits 712, 714 and 716, whichoutput to respective electrodes 704, 706 and 708 and thence via openings710 to conduit 700. It is seen that preferably electrodes 704 and 708are grounded, while electrode 706 receives AC current at high voltage,preferably at mains frequencies.

[0168] The arrangement of FIG. 7 is preferred for electroheating ofrelatively viscous materials, since it generally prevents physicalcontact between the viscous materials and electrodes 704, 706 and 708.Also, there are no obstacles to flow and no change of diameter, so thevelocity is high and uniform.

[0169] Reference is now made to FIG. 8, which is a simplified sectionalillustration of a material treatment system and methodology constructedand operative in accordance with yet another preferred embodiment of thepresent invention.

[0170] As seen in FIG. 8, the material treatment system and methodologyof FIG. 8 employs a thermally insulated enclosure 800, the interior ofwhich is in communication with the ambient atmosphere via a vacuum pump802, which preferably maintains the interior of enclosure 800 atsubatmospheric pressure, typically about 29″ of mercury.

[0171] Enclosure 800 is partially filled with a cooling liquid 804,preferably water, which boils at room temperature at the subatmosphericpressure of 29″ of mercury within enclosure 800. A scraped surface heatexchanger 806 is disposed in enclosure 800 and includes a conduit 808,part of which extends through the liquid 804. Heated fluid material 810,such as an electroheated food product, passes through the conduit 808,in thermal contact with the walls thereof, and becomes cooled byevaporating the liquid 804.

[0172] In accordance with a preferred embodiment of the presentinvention, an agitator 812, typically in the form of an elongate shaft814, having outwardly extending vanes 816, is disposed in conduit 808,and rotated therein about an axis 818, as by a motor 820, to provideenhanced uniformity of thermal contact between the heated fluid material810 and the walls of the conduit 808.

[0173] Disposed inside enclosure 800 above the level of the coolingliquid 804 is a condensing coil 822. A coolant, such as water,preferably passes through condensing coil 822.

[0174] The system of FIG. 8 also preferably comprises a reservoir 824 influid communication with the interior of enclosure 800, such as by meansof a flexible tube 826. Reservoir 824 preferably contains cooling liquid804 which can flow into the interior of enclosure 800 via flexible tube826. Another flexible tube 828 is preferably provided to ensure that thevacuum maintained inside enclosure 800 is also maintained insidereservoir 824. Reservoir 824 is preferably mounted onto a vertical track(not shown) for selectable vertical positioning relative to enclosure800, thereby to enable ease of selection of the level of cooling liquid804 in enclosure 800. This level effectively controls the amount ofcooling produced by the system by determining how much of the scrapedsurface heat exchanger 806 is disposed in the liquid 804.

[0175] It will be appreciated by persons skilled in the art that thepresent invention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove as well as variations and modifications whichwould occur to persons skilled in the art upon reading the specificationand which are not in the prior art.

1. A vacuum heat exchange system comprising: a container partiallyfilled with a liquid and maintained under a vacuum; a first heatexchanger disposed in said liquid in said container, said first heatexchanger receiving a first fluid material, heating said liquid andthereby cooling said first fluid material; and a second heat exchangerdisposed outside of said liquid in said container, said second heatexchanger receiving a second fluid material and being heated by vaporsof said liquid thereby heating said second fluid material, at least oneof said first and second heat exchangers including an agitator foragitating said fluid material passing therethrough to enhance heatexchange generally throughout said fluid material.
 2. A vacuum heatexchange system according to claim 1 and wherein both of said first andsecond heat exchangers include an agitator for agitating said fluidmaterial passing therethrough to enhance heat exchange generallythroughout said fluid material.
 3. A vacuum heat exchange systemaccording to claim 1 and wherein first heat exchanger includes anagitator for agitating said first fluid material passing therethrough toenhance heat exchange generally throughout said first fluid material. 4.A vacuum heat exchange system according to claim 1 and wherein secondheat exchanger includes an agitator for agitating said second fluidmaterial passing therethrough to enhance heat exchange generallythroughout said second fluid material.
 5. A vacuum heat exchange systemaccording to claim 1 and wherein at least one of said first and secondheat exchangers comprises a scraped surface heat exchanger.
 6. A vacuumheat exchange system according to claim 1 and also comprising: anelectroheater for heating said first fluid material prior to receiptthereof by said first heat exchanger.
 7. A vacuum heat exchange systemaccording to claim 1 and also comprising: an electroheater for receivingsaid second fluid material from said second heat exchanger.
 8. A vacuumheat exchange system according to claim 1 wherein said first and secondfluid materials are the same material at different temperatures and alsocomprising: an electroheater for heating said first fluid material priorto receipt thereof by said first heat exchanger and wherein said firstfluid material is received by said electroheater from said second heatexchanger.
 9. A vacuum heat exchange system according to claim 2 whereinsaid first and second fluid materials are the same material at differenttemperatures and also comprising: an electroheater for heating saidfirst fluid material prior to receipt thereof by said first heatexchanger and wherein said first fluid material is received by saidelectroheater from said second heat exchanger.
 10. A vacuum heatexchange system according to claim 5 wherein said first and second fluidmaterials are the same material at different temperatures and alsocomprising: an electroheater for heating said first fluid material priorto receipt thereof by said first heat exchanger and wherein said firstfluid material is received by said electroheater from said second heatexchanger.
 11. A material treatment system comprising: an electroheateroperative to rapidly heat a first fluid material; and a vacuum heatexchange subsystem operative to rapidly cool said first fluid materialfollowing electroheating thereof, said vacuum heat exchange subsystemcomprising: a container partially filled with a liquid and maintainedunder a vacuum; a first heat exchanger disposed in said liquid in saidcontainer, said first heat exchanger receiving said first fluidmaterial, heating said liquid and thereby cooling said first fluidmaterial, and a second heat exchanger disposed outside of said liquid insaid containers said second heat exchanger receiving a second fluidmaterial and being heated by vapors of said liquid, thereby heating saidsecond fluid material, at least one of said first and second heatexchangers including an agitator for agitating said fluid materialpassing therethrough to enhance heat exchange generally throughout saidfluid material.
 12. A material treatment system according to claim 11and wherein both of said first and second heat exchangers include anagitator for agitating said fluid material passing therethrough toenhance heat exchange generally throughout said fluid material.
 13. Amaterial treatment system according to claim 11 and wherein first heatexchanger includes an agitator for agitating said first fluid materialpassing therethrough to enhance heat exchange generally throughout saidfirst fluid material.
 14. A material treatment system according to claim11 and wherein second heat exchanger includes an agitator for agitatingsaid second fluid material passing therethrough to enhance heat exchangegenerally throughout said second fluid material.
 15. A materialtreatment system according to claim 11 and wherein at least one of saidfirst and second heat exchangers comprises a scraped surface heatexchanger.
 16. A material treatment system according to claim 11 andwherein said electroheater supplies said first fluid material to aholding tank, prior to receipt of said first fluid material by saidfirst heat exchanger.
 17. A material treatment system according to claim11 and wherein said electroheater receives said second fluid materialfrom said second heat exchanger.
 18. A material treatment systemaccording to claim 11 wherein said first and second fluid materials arethe same material at different temperatures and wherein saidelectroheater heats said first fluid material prior to receipt thereofby said first heat exchanger and wherein said first fluid material isreceived by said electroheater from said second heat exchanger.
 19. Amaterial treatment system according to claim 12 wherein said first andsecond fluid materials are the same material at different temperaturesand wherein said electroheater heats said first fluid material prior toreceipt thereof by said first heat exchanger and wherein said firstfluid material is received by said electroheater from said second heatexchanger.
 20. A material treatment system according to claim 15 whereinsaid first and second fluid materials are the same material at differenttemperatures and wherein said electroheater heats said first fluidmaterial prior to receipt thereof by said first heat exchanger andwherein said first fluid material is received by said electroheater fromsaid second heat exchanger.
 21. A material treatment system comprising:an electroheater operative to rapidly heat a first fluid material; afirst vacuum heat exchange subsystem operative to rapidly cool saidfirst fluid material following electroheating thereof, said first vacuumheat exchange subsystem comprising: a container partially filled with aliquid and maintained under a vacuum; a first heat exchanger disposed insaid liquid in said container, said first heat exchanger receiving saidfirst fluid material, heating said liquid and thereby cooling said firstfluid material; and a second heat exchanger disposed outside of saidliquid in said container said second heat exchanger receiving a secondfluid material and being heated by vapors of said liquid, therebyheating said second fluid material, at least one of said first andsecond heat exchangers including an agitator for agitating said fluidmaterial passing therethrough to enhance heat exchange generallythroughout said fluid material; and a second vacuum heat exchangesubsystem operative to preheat said first fluid material prior toelectroheating thereof, said second vacuum heat exchange subsystemcomprising: a container partially filled with a liquid and maintainedunder a vacuum; a third heat exchanger disposed in said liquid in saidcontainer, said third heat exchanger receiving a third fluid material,heating said liquid and thereby cooling said third fluid material; and afourth heat exchanger disposed outside of said liquid in said container,said fourth heat exchanger receiving said first fluid material and beingheated by vapors of said liquid, thereby heating said first fluidmaterial, at least one of said third and fourth heat exchangersincluding an agitator for agitating said fluid material passingtherethrough to enhance heat exchange generally throughout said fluidmaterial.
 22. A material treatment system according to claim 21 andwherein both of said first and second heat exchangers include anagitator for agitating said fluid material passing therethrough toenhance heat exchange generally throughout said fluid material.
 23. Amaterial treatment system according to claim 21 and wherein first heatexchanger includes an agitator for agitating said first fluid materialpassing therethrough to enhance heat exchange generally throughout saidfirst fluid material.
 24. A material treatment system according to claim21 and wherein second heat exchanger includes an agitator for agitatingsaid second fluid material passing therethrough to enhance heat exchangegenerally throughout said second fluid material.
 25. A materialtreatment system according to claim 21 and wherein at least one of saidfirst and second heat exchangers comprises a scraped surface heatexchanger.
 26. A material treatment system according to claim 21 andwherein said electroheater supplies said first fluid material to aholding tank, prior to receipt of said first fluid material by saidfirst heat exchanger.
 27. A material treatment system according to claim21 and wherein both of said third and fourth heat exchangers include anagitator for agitating said fluid material passing therethrough toenhance heat exchange generally throughout said fluid material.
 28. Amaterial treatment system according to claim 21 and wherein third heatexchanger includes an agitator for agitating said third fluid materialpassing therethrough to enhance heat exchange generally throughout saidthird fluid material.
 29. A material treatment system according to claim21 and wherein fourth heat exchanger includes an agitator for agitatingsaid first fluid material passing therethrough to enhance heat exchangegenerally throughout said first fluid material.
 30. A material treatmentsystem according to claim 21 and wherein at least one of said third andfourth heat exchangers comprises a scraped surface heat exchanger.
 31. Apackaged food product characterized in: having a viscosity exceedingapproximately 5,000 centipoise; being sterilized; and being asepticallypackaged.
 32. A packaged food product according to claim 31 and having apH exceeding approximately 4.5.
 33. A packaged humus food productcharacterized in: being sterilized; and being aseptically packaged. 34.A packaged egg food product characterized in: being sterilized; andbeing aseptically packaged.
 35. A packaged egg food productcharacterized in: being sterilized; being aseptically filled and sealedfollowing sterilization and cooling thereof.
 36. A packaged egg foodproduct according to claim 34 and wherein said egg food product iscoagulated.
 37. A packaged egg food product according to claim 35 andwherein said egg food product is coagulated.
 38. A packaged egg foodproduct characterized in: being pasteurized to at least 75 degreesCentigrade; being aseptically filled and sealed following pasteurizationand cooling thereof; and being liquid.
 39. A vacuum heat exchange methodcomprising: partially filling a container maintained under a vacuum witha liquid; receiving a first fluid material in a first heat exchangerdisposed in said liquid in said containers heating said liquid andthereby cooling said first fluid material; and receiving a second fluidmaterial in a second heat exchanger disposed outside of said liquid insaid container, heating said second heat exchanger by vapors of saidliquid, thereby heating said second fluid material, where at least oneof said first and second heat exchangers includes an agitator foragitating said fluid material passing therethrough to enhance heatexchange generally throughout said fluid material.
 40. A vacuum heatexchange method according to claim 39 and wherein both of said first andsecond heat exchangers include an agitator for agitating said fluidmaterial passing therethrough to enhance heat exchange generallythroughout said fluid material.
 41. A vacuum heat exchange methodaccording to claim 39 and wherein first heat exchanger includes anagitator for agitating said first fluid material passing therethrough toenhance heat exchange generally throughout said first fluid material.42. A vacuum heat exchange method according to claim 39 and whereinsecond heat exchanger includes an agitator for agitating said secondfluid material passing therethrough to enhance heat exchange generallythroughout said second fluid material.
 43. A vacuum heat exchange methodaccording to claim 39 and wherein at least one of said first and secondheat exchangers comprises a scraped surface heat exchanger.
 44. A vacuumheat exchange method according to claim 39 and also comprising: heatingsaid first fluid material in an electroheater prior to receipt thereofby said first heat exchanger.
 45. A vacuum heat exchange methodaccording to claim 39 and also comprising: receiving said second fluidmaterial into an electroheater from said second heat exchanger.
 46. Avacuum heat exchange method according to claim 39 wherein said first andsecond fluid materials are the same material at different temperaturesand also comprising: receiving said first fluid material from saidsecond heat exchanger; and heating said first fluid material using anelectroheater prior to receipt thereof by said first heat exchanger. 47.A vacuum heat exchange method according to claim 40 wherein said firstand second fluid materials are the same material at differenttemperatures and also comprising: receiving said first fluid materialfrom said second heat exchanger; and heating said first fluid materialusing an electroheater prior to receipt thereof by said first heatexchanger.
 48. A vacuum heat exchange method according to claim 43wherein said first and second fluid materials are the same material atdifferent temperatures and also comprising: receiving said first fluidmaterial from said second heat exchanger; and heating said first fluidmaterial using an electroheater prior to receipt thereof by said firstheat exchanger.
 49. A material treatment method comprising: rapidlyheating a first fluid material using an electroheater; and rapidlycooling, said first fluid material following electroheating thereof by:partially filling a container maintained under a vacuum with a liquid;receiving said first fluid material in a first heat exchanger disposedin said liquid in said container, heating said liquid and therebycooling said first fluid material; and receiving a second fluid materialin a second heat exchanger disposed outside of said liquid in saidcontainer, heating said second heat exchanger by vapors of said liquid,thereby heating said second fluid material, where at least one of saidfirst and second heat exchangers includes an agitator for agitating saidfluid material passing therethrough to enhance heat exchange generallythroughout said fluid material.
 50. A material treatment methodaccording to claim 49 and wherein both of said first and second heatexchangers include an agitator for agitating said fluid material passingtherethrough to enhance heat exchange generally throughout said fluidmaterial.
 51. A material treatment method according to claim 49 andwherein first heat exchanger includes an agitator for agitating saidfirst fluid material passing therethrough to enhance heat exchangegenerally throughout said first fluid material.
 52. A material treatmentmethod according to claim 49 and wherein second heat exchanger includesan agitator for agitating said second fluid material passingtherethrough to enhance heat exchange generally throughout said secondfluid material.
 53. A material treatment method according to claim 49and wherein at least one of said first and second heat exchangerscomprises a scraped surface heat exchanger.
 54. A material treatmentmethod according to claim 49 and comprising: supplying said first fluidmaterial to a holding tank from said electroheater prior to receivingsaid first fluid material in said first heat exchanger.
 55. A materialtreatment method according to claim 49 and comprising: receiving saidsecond fluid material into said electroheater from said second heatexchanger.
 56. A material treatment method according to claim 49 whereinsaid first and second fluid materials are the same material at differenttemperatures and comprising: receiving said first fluid material by saidelectroheater from said second heat exchanger; and heating said firstfluid material in said electroheater prior to receipt thereof by saidfirst heat exchanger.
 57. A material treatment method according to claim50 wherein said first and second fluid materials are the same materialat different temperatures and comprising: receiving said first fluidmaterial by said electroheater from said second heat exchanger; andheating said first fluid material in said electroheater prior to receiptthereof by said first heat exchanger.
 58. A material treatment methodaccording to claim 53 wherein said first and second fluid materials arethe same material at different temperatures and comprising: receivingsaid first fluid material by said electroheater from said second heatexchanger; and heating said first fluid material in said electroheaterprior to receipt thereof by said first heat exchanger.
 59. A materialtreatment method comprising: rapidly heating a first fluid materialusing an electroheater; and rapidly cooling said first fluid materialfollowing electroheating thereof by: partially filling a containermaintained under a vacuum with a liquid; receiving a first fluidmaterial in a first heat exchanger disposed in said liquid in saidcontainer, heating said liquid and thereby cooling said first fluidmaterial; and receiving a second fluid material in a second heatexchanger disposed outside of said liquid in said container, heatingsaid second heat exchanger by vapors of said liquid, thereby heatingsaid second fluid material, where at least one of said first and secondheat exchangers includes an agitator for agitating said fluid materialpassing therethrough to enhance heat exchanger generally throughout saidfluid material; and preheating said first fluid material prior toelectroheating thereof by: partially filling a container maintainedunder a vacuum with a liquid; receiving a third fluid material in athird heat exchanger disposed in said liquid in said container, heatingsaid liquid and thereby cooling said third fluid material; and receivingsaid first fluid material in a fourth heat exchanger disposed outside ofsaid liquid in said container, heating said fourth heat exchanger byvapors of said liquid, thereby heating said first fluid material, whereat least one of said third and fourth heat exchangers includes anagitator for agitating said fluid material passing therethrough toenhance heat exchange generally throughout said fluid material.
 60. Amaterial treatment method according to claim 59 and wherein both of saidfirst and second heat exchangers include an agitator for agitating saidfluid material passing therethrough to enhance heat exchange generallythroughout said fluid material.
 61. A material treatment methodaccording to claim 59 and wherein first heat exchanger includes anagitator for agitating said first fluid material passing therethrough toenhance heat exchanger generally throughout said first fluid material.62. A material treatment method according to claim 59 and wherein secondheat exchanger includes an agitator for agitating said second fluidmaterial passing therethrough to enhance heat exchange generallythroughout said second fluid material.
 63. A material treatment methodaccording to claim 59 and wherein at least one of said first and secondheat exchangers comprises a scraped surface heat exchanger.
 64. Amaterial treatment method according to claim 59 and comprising:supplying said first fluid material to a holding tank from saidelectroheater prior to receiving said first fluid material in said firstheat exchanger.
 65. A material treatment method according to claim 59and wherein both of said third and fourth heat exchangers include anagitator for agitating said fluid material passing therethrough toenhance heat exchange generally throughout said fluid material.
 66. Amaterial treatment method according to claim 59 and wherein third heatexchanger includes an agitator for agitating said third fluid materialpassing therethrough to enhance heat exchange generally throughout saidthird fluid material.
 67. A material treatment method according to claim59 and wherein fourth heat exchanger includes an agitator for agitatingsaid first fluid material passing therethrough to enhance heat exchangegenerally throughout said first fluid material.
 68. A material treatmentmethod according to claim 59 and wherein at least one of said third andfourth heat exchangers comprises a scraped surface heat exchanger.
 69. Amethod of preparing a packaged food product comprising: producing a foodproduct having a viscosity exceeding approximately 5,000 centipoise;sterilizing said food product; and aseptically packaging said foodproduct.
 70. A method of preparing a packaged food product according toclaim 69 and wherein said packaged food product has a pH exceedingapproximately 4.5.
 71. A method of preparing a packaged humus foodproduct comprising: sterilizing said humus food product; and asepticallypackaging said humus food product.
 72. A method of preparing a packagedegg food product comprising: sterilizing said egg food product; andaseptically packaging said egg food product.
 73. A method of preparing apackaged egg food product comprising: sterilizing said egg food product;cooling said egg food product: and aseptically filling and sealing saidegg food product in a package.
 74. A method of preparing a packaged eggfood product according to claim 72 and wherein said egg food product iscoagulated.
 75. A method of preparing a packaged egg food productaccording to claim 73 and wherein said egg food product is coagulated.76. A method of preparing a packaged liquid egg food product comprising:pasteurizing said liquid egg food product to at least 75 degreesCentigrade; cooling said liquid egg food product; and asepticallyfilling and sealing said liquid egg food product in a package.